This invention relates to collapsible containers.
One class of collapsible container has walls formed of a foldable material. These containers are designed to be stored in compressed shape for use such as for the addition of liquid at a later date.
One prior art type of such collapsible container is disclosed in U.S. Pat. No. 3,101,921 to Price, issued Aug. 27, 1963. This collapsible container is designed for aircraft. Such containers are generally large having a capacity of 50 to 100 gallons and commonly requiring an uncollapsed dimension of between ten feet in length and five feet in diameter.
These prior art fuel tanks have a disadvantage in that they are not suitable for many uses such as for use with an automobile. Indeed, when fully inflated with fuel, additional rigid supports are needed for strength to maintain the integrity of the elastomeric walls.
Another prior art type of collapsible container is a collapsible container used for soft drinks and the like. One such collapsible container is described in U.S. Pat. No. 4,492,313. This type of collapsible container is generally cylindrical having a diameter of three or four inches and is not designed to support heavy weight. Indentations in the base and the neck of the collapsible containers used for soft drinks form handles for expanding the container if desired.
The collapsible containers used for soft drinks have several disadvantages, such as: (1) they can not be readily expanded because of the absence of easily graspable handles; (2) they are usually too small in diameter to contain a significant amount of fuel; (3) they rely upon a single opening both to pour the liquid and to serve as an air vent; and (4) they are not designed to support heavy weight.